Hydrogen Production Technologies: From Fossil Fuels toward Renewable Sources. A Mini Review

Abstract

The global economic growth, the increase in the population, and advances in technology lead to an increment in the global primary energy demand. Considering that most of this energy is currently supplied by fossil fuels, a considerable amount of greenhouse gases are emitted, contributing to climate change, which is the reason why the next European Union binding agreement is focused on reducing carbon emissions using hydrogen. This study reviews different technologies for hydrogen production using renewable and non-renewable resources. Furthermore, a comparative analysis is performed on renewablebased technologies to evaluate which technologies are economically and energetically more promising. The results show how biomass-based technologies allow for a similar hydrogen yield compared to those obtained with water-based technologies but with higher energy efficiencies and lower operational costs. More specifically, biomass gasification and steam reforming obtained a proper balance between the studied parameters, with gasification being the technique that allows for higher hydrogen yields, while steam reforming is more energy-efficient. Nevertheless, the application of hydrogen as the energy vector of the future requires both the use of renewable feedstocks with a sustainable energy source. This combination would potentially produce green hydrogen while reducing carbon dioxide emissions, limiting global climate change, and, thus, achieving the so-called hydrogen economy.

WITHDRAWN: Effects of equivalence ratio and wall properties on the heat transfer characteristics of microchannel reactors for hydrogen production

“…Industrial production is mainly from steam reforming of natural gas, oil reforming, or coal gasi cation [5,6]. A small percentage is also produced using more energy-intensive methods such as the electrolysis of water [7,8].…”

Plasma modified and tailored defective electrocatalysts for water electrolysis and hydrogen fuel cells

“…The methods for industrial hydrogen production can be divided into three main categories, namely thermal processes, electrolytic processes, and photolytic processes including steam methane reforming (efficiency of 70%-80%), coal gasification ($60%), partial oxidation of coal ($55%), H 2 S methane reforming ($50%), landfill gas dry reformation ($47%-58%), partial oxidation of heavy oil ($70%), naphtha reforming, steam reforming of waste oil ($75%), steam-iron process ($46%), chloralkali electrolysis, grid electrolysis of water ($27%), solar/photovoltaic electrolysis of water ($10%), high-temperature electrolysis of water ($48%), thermochemical water splitting (35-45%), biomass gasification (45%-50%), photobiological process (<1%), photolysis of water (<10%), photoelectrochemical decomposition of water, and photocatalytic decomposition of water, where the numbers in parentheses represent the typical efficiency. [61][62][63][64] The conversion paths from the energy sources to hydrogen are illustrated in Figure 1A. The use of fossil fuels to produce hydrogen emits a large amount of carbon dioxide, which severely restricts the development of green hydrogen energy.…”

Selective Photocatalytic Dehydrogenation of Formic Acid by an In Situ-Restructured Copper-Postmetalated Metal–Organic Framework under Visible Light

“…Therefore, it needs to be extracted through different processes. Molecular hydrogen has experienced a global resurgence lately as an energy carrier and a secondary source of green energy . Despite being characterized by a low atomic weight, low boiling point, high flammability range, and extremely low density, this species possesses an enormous gravimetric energy (chemical energy per mass unit) of 120 kJ·g –1 , which surpasses those of methane, gasoline, and ethanol (56, 47, and 30 kJ·g –1 , respectively) .…”

“…Molecular hydrogen has experienced a global resurgence lately as an energy carrier and a secondary source of green energy. 2 Despite being characterized by a low atomic weight, low boiling point, high flammability range, and extremely low density, this species possesses an enormous gravimetric energy (chemical energy per mass unit) of 120 kJ• g −1 , which surpasses those of methane, gasoline, and ethanol (56,47, and 30 kJ•g −1 , respectively). 3 Therefore, the development of cheap, safe, and effective hydrogen on-site catalytic production systems has been gaining much attention in the past few years.…”